1. The Field of the Invention
Embodiments of the invention relate to optical modules and methods of operating optical modules.
2. Background of the Invention
Communication modules, such as electronic or optoelectronic transceivers or transponder modules, are increasingly used in electronic and optoelectronic communication. Such optical modules communicate with a host device printed circuit board by transmitting and/or receiving electrical data signals to and/or from the host device printed circuit board. The electrical data signals may also be transmitted by the optical module outside a host device as optical and/or electrical data signals. Many optical modules include optoelectronic components such as transmitter optical subassemblies and/or receiver optical subassemblies to convert between the electrical and optical domains.
Generally, a receiver optical subassembly converts an optical signal received from an optical fiber or other source to an electrical signal provided to the host device, while a transmitter optical subassembly transforms an electrical signal received from the host device to an optical signal emitted onto an optical fiber or other transmission medium. A photodiode or similar optical receiver contained by the receiver transforms the optical signal to the electrical signal. A laser diode or similar optical transmitter contained within the transmitter is driven to emit an optical signal representing the electrical signal received from the host device.
One difficulty related to optical module design and operation is the ability to control the power level of the optical signal, often referred to as attenuation, particularly within the optical module itself.